In general, if the app is not checking mail (the default is once every 15 minutes), then the most common culprits are: – For Android 6.0 and newer, its so called Doze mode – Memory optimizer apps and battery optimizer apps (e.g. Clean Master) – Sometimes those are third party apps, sometimes built into the phone’s system software (Xiaomi, Huawei, possibly others) — Android 6 and newer and its “Doze Mode” Doze Mode is where Android will not let apps run in the background as often as they need to while the phone is stationary.
This kicks in after a few hours on Android 6 and sooner on Android 7.
The app will prompt you to “whitelist” (exclude) it from this “Doze Mode” within a day after installing if it detects Android 6 or newer.
To check, please bring up AquaMail settings -> mail, receiving.
If the app is not already whitelisted, there will be a green panel / button / message / prompt asking you to do this.
There are several “battery optimizer” apps (third party or things built into the phone’s software) which deliberately block the ability of apps to access the network or to work in the background.
One such app is Clean Master.
If you use one, please try to “exclude” or “whitelist” AquaMail there.
On Samsung phones please see Phone Settings -> Device Maintenance -> Battery. You’ll want want the “power saving mode” to be OFF.
And below that, if you scroll down, you do not want Aqua Mail to be listed in “always sleeping apps”. You may want to put it under “unmonitored apps” so it stays out of harm’s way.
There were several reports recently specific to Xiaomi MIUI: Apparently MIUI has some sort of “battery optimizer” thing built-in – Which prevents apps from accessing the network when in the background – This is in the phone’s system Settings app -> Additional Settings -> Battery & Performance -> Manage apps battery usage Gmail and a few other apps are already whitelisted there. Not AquaMail though, so this has to be done manually.
Recent Huawei phones have a built-in “battery optimizer” too.
It’s in the phone’s Settings app -> Advanced settings -> Battery manager -> Protected apps -> and you will want to set AquaMail to “Protected” here.
ASUS phones too have a built-in “battery optimizer” called “mobile manager”.
The section you want there is labeled “auto-start manager” and Aqua Mail needs to be set to “allow”.